Die-casting machine



Aug. 9, 1927.

E. THIESLACK DIE CASTING MACHINE 2 'sheets-sheet 1 Filed March 3. 1927 Augt 9, 1927.

E. 'rHlEsL'AcK DIE CASTING MACHINE Filed March 3. 1927 2 Sheets-Sheet 2 Patented Aug. 9, 1927.

PATENT OFFICE.

EMIL THIESLACK, OF BERLIN, GERMANY.

DIE-CASTING- MACHINE.

Application led March 3, 1927, Serial No.

My invention relates to die-casting machines and it is an object of my invention to provide an improved. type of valve for controlling tlie flow of molten metal from the melting to the casting reservoir. v

To this end, instead of the usual solid piston valve, I provide a rotary or reciprocating sleeve for controlling the opening through which the molten metal is flowing.

It is another object ot my invention to provide means by which the supply of tluid under pressure to the casting tank is op,-

v eratively connected with the valve, and to this end I provide a connection by which the supply'is regulated in time with the motion of the valve.

lVith the usual type ot valve a cylinder is provided defining an opening which is adapted to be controlled by a solid piston valve in the cylinder. The valve must `be ground into its cylinder very accurately, a process involving considerable labour, and yet the valve soon becomes inoperative, particularly'when aluminium is cast, as the valve and its cylinder are attacked by the molten metal.

Another drawback of the solid piston valve is that the pressure of the fluid expelling the metal from the casting tank reacts onthe comparatively large area of the piston, causing considerable resistance to the motion of the valve and corresponding wear and leakage.

These drawbacks are overcome in my invention where the functions of the parts constituting the valve are exchanged, the cylinder' or sleeve being adapted to be moved, i. e., reciprocated or rotated, with respectl to the piston which is constituted by 'a hollow boss defining in its wall the opening for the molten metal. The opening is controlled byreciproeation or rotation of the sleeve and the reaction on the sleeve is practically nil as the pressure of the iluid acts only on the small area of the openincr and is otherwise absorbed by the/boss. (Irinding is not required here as the sleeve tits the boss tightly enough without that.

The valve may be operated by hand or mechanically, and automatic means such as a pull-back spring may be provided for returning its sleeve to initial position after it has been displaced or rotated on the boss.

In the drawing, machines which are operated by hand and by fluid under pressure, i

172,508, and in Germany October 30, 1,925.

and reciprocating and "rotary valve sleeves are illustrated by Way of example. Fig. 1 is an elevation, partly in section, ofa hand-operated die-casting machine,

Fig. 2 is a similar elevation showing a fi i 1 id-operated machine,

. Figs. 3 and 4 are elevations on a larger scale, partly in section, illustrating a valve having a rotary sleeve, open and closed, re`

spectively.

Referring now to Fig. 1, 3 is a boss projecting from a partition intermediatethe casting reservoir 1 and thel melting reservoir, 2 is an opening in the wall of the boss, 4 isl a sleeve adapted io reciprocate on said boss.I 5 is a lever fl'xlerumed on the top plate of the melting reservoir and operatively connected with a rod extending upwards from the sleeve 4, 27 is a spring on the rod of the sleeve, which counteracts downward motion of the sleeve 4` 6 is a handle for operating the lever 5, 7 is a lever connected with the lever 5 by a slotted link, 8 is a valve at the top of a tank 9 containing air' or any other Huid under ressure, and l0 is a pipe line connecting tilde chamber of the valve 8 with the casting reservoir 10. l

The operation of this machine is as follows: In the initial position of the sleeve 4 it uncovers the opening 2 so that molten metal from the melting reservoir enters the casting reservoir 1. When the casting reservoir has been charged, the handle 6 is depressed and the opening 2 is .closed by the sleeve 4 through the connection described. After a given time which is determined Iby the play between the levers 5 and 7, the

yvalve 8 will open and admit Huid underl pressure to the casting reservoir 1, the contents of which are then expelled. The valve 8, as described in my coepending U. S, application No. 31,182 tiled May 18, 1925, andPatent No. 1,611,614 granted Dec. 21, 1926y -is so constructed that it will close autoinatibally when the casting operation has been performed, the excess of fluid heilig discharged through a groove.

Referring nowV to Fig. 2, the sleeve 4 is in this case operated by the pressure of a fluid, for instance, air. 11 is a fluid tank, 18 is a pipe line, 14 is a cylinder to which the pipe line is connected, 15 is a piston in the cylinder, 16 is a pull-back spring inserted` between the bottom of the cylinder and the piston, 17 is a rod connecting the piston and the sleeve 4, and 18 is a lever similar to the lever 5 in Fig. 1 which is fulcrumed on the melting reservoir as described, and pivotally connected with the rod 17.

21 is a lever connected with a valve similar to the valve 8, Fig. 1, and adapted to be engaged by the end 19 of the lever 18, 20 is a pawl on the end of the lever 21 which cooperates with the lever 18, 24 is a pullback spring for the valve, 22 is a' fluid tank similar to the tank 9, Fig. 1, and 23 is a pipe line which connects the chamber of the valve with the casting reservoir 1. The valves of the tanks 11 and 22 are constructed as explained above with referencev to the valve 8, Fig. 1, that is, so as to allow excess luid to escape. As soon as the valve in the tank 22 has been operated, the end 19 of the lever 18 slides oft' the pawl 20 and the valve is closed by its'spring 24, excess iluid escaping by its vent groove. When the fluid in the cylinder 14 ceases to operate the piston 15 .is returned to its initial position by the Spring 16, the sleeve 4 lays o en the opening l2, and the machine is reacy for the next operation.

In the modification illustrated in Figs. 3 and 4, the sleeve 4 is dapted to be rotated instead of being reciiroc'ated. Other# Wise the construction of the boss ,3' with its opening 2 and the sleeve 4 on the boss is similar `to that described, and these. parts have therefore been marked with corresponding and primed reference numerals. 30 is a passage in the wall of the sleeve 4 which, may re ister with the opening 2 in the boss 3 and, when the passage so registers, as shown in Fig. 3, the casting reser-l voir l is charged from the melting reser voir. Fig. 4 shows the part rotated from the position in Fig. 3 so that the opening 2 is covered by the Wall of the sleeve 4.

I claim:

A die casting machine comprising a melting reservoir, a casting reservoir arranged immediately therebeneath, the bottom of the melting reservoir serving as the top of the casting reservoir, an upri ht hollow boss rising from the bottom of t e melting reservoir and provided in its wall with a lateral opening which serves to establish communication between the reservoirs, a sleeve-like valve movably mounted exteriorly of the boss for controlling the passage yof fluids through said opening, means for supplying Huid underV pressure to said casting reservoir to facilitate ejecting of the vcontents subsequent to the closing of the opening by the sleeve, and the top of the boss being closed so as to prevent action of the pressure supply means on the valve.

In testimony whereof, I have signed my name to this specification.

EMIL THIESLACK. 

